Working on supporting large stacks in the RTOS, we end up with something like this in the linker script:
. = ALIGN(16);
.thread_stack_1 : CAPALIGN
{
.thread_1_stack_start = .;
. += 0x10000;
.thread_1_stack_end = .;
}
The start of the thread stack ends up 16-byte aligned, which is not sufficient for the 0x10000-byte chunk. I believe you can minimally reproduce this by starting with something like . = 0x8000010;, if not try setting a large stack size in the hello-world example in the RTOS and just delete the bits in sdk/xmake.lua that reject it.